a way to randomize pairs
Quite common in Japan, this is known here as amidakuji. It is simply a way to shuffle a set of pairs so they each end up with a random partner.
How to use
By default the top set is A-J, and the bottom is 1-10, but you can change that easily just by clicking each name.
Add or remove new ladder rungs by clicking, or hit the random button to generate a set of random rungs.
Hit the coloured set markers at the top to show which route leads to the item's new partner.